Quarter	US dollars
1999-03-31	2885
1999-06-30	2455
1999-09-30	2627
1999-12-31	2495
2000-03-31	2946
2000-06-30	3959
2000-09-30	2759
2000-12-31	2677
2001-03-31	2888
2001-06-30	2707
2001-09-30	3105
2001-12-31	4124
2002-03-31	2779
2002-06-30	3995
2002-09-30	2843
2002-12-31	2793
2003-03-31	3598
2003-06-30	2695
2003-09-30	2819
2003-12-31	3226
2004-03-31	2791
2004-06-30	2369
2004-09-30	2697
2004-12-31	2645
2005-03-31	3463
2005-06-30	2050
2005-09-30	2163
2005-12-31	2745
2006-03-31	3143
2006-06-30	3336
2006-09-30	3036
2006-12-31	3451
2007-03-31	3358
2007-06-30	3286
2007-09-30	2647
2007-12-31	3707
2008-03-31	5324
2008-06-30	5452
2008-09-30	3829
2008-12-31	824
2009-03-31	1244
2009-06-30	1714
2009-09-30	1654
2009-12-31	396
2010-03-31	1706
2010-06-30	2394
2010-09-30	1846
2010-12-31	1259
2011-03-31	1194
2011-06-30	1097
2011-09-30	1349
2011-12-31	2049
2012-03-31	1802
2012-06-30	1051
2012-09-30	1557
2012-12-31	1789
2013-03-31	2668
2013-06-30	2551
2013-09-30	1654
2013-12-31	911
2014-03-31	1929
2014-06-30	1002
2014-09-30	1108
2014-12-31	2174
2015-03-31	1128
2015-06-30	1032
2015-09-30	2008
2015-12-31	1748
2016-03-31	3035
2016-06-30	3003
2016-09-30	3118
2016-12-31	4472
2017-03-31	5566
2017-06-30	2403
2017-09-30	2361
2017-12-31	1847
2018-03-31	2708
2018-06-30	2535
2018-09-30	3114
2018-12-31	3615
2019-03-31	3352
2019-06-30	2224
2019-09-30	3595
2019-12-31	4062
2020-03-31	4081
2020-06-30	4465
2020-09-30	3788
2020-12-31	6111
2021-03-31	6005
2021-06-30	3868
2021-09-30	4377
2021-12-31	3959
2022-03-31	5199
2022-06-30	3403
2022-09-30	2760
2022-12-31	4104
2023-03-31	2813
2023-06-30	3256
2023-09-30	3021